Apparatus for drying and cooling particulated material



July 19, 1966 H. TILLMANNS 3,261,109

APPARATUS FOR DRYING AND COOLING PARTICULATED MATERIAL Filed NOV. 20, 1964 United States Patent Claims. in. 34 171 The present invention relates to an apparatus for drying and cooling particulated material and used, for instance, in the sugar industry for drying sugar crystails. Apparatus of this type are known in the art which consist of an elon- :gated substantially vertically arranged housing having an upper drying zone and a lower cooling zone and in which the material to be dried is caused to pass in finely divided form from the upper to the lower end of the housing, whereas the treating medium is passed in countercurrent to the material through the housing. In known apparatus of this type the cooling air is fed into the lower end of. the cooling zone of the apparatus and part of this cooling air is branched off at the upper end of the cooling zone, heated and passed through the drying zone.

A combined drying and cooling apparatus for particulated material of this type requires a considerably greater amount of air in the cooling zone than is necessary in the drying zone and considerable difiiculties are encountered in the apparatus of this type to assure that only the necessary amount of air entering as cooling air at the lower end or the cooling zone is passed through the drying zone of the apparatus.

It is an object ot the present invention to provide for a combined drying and cooling apparatus for particulated material in which the cooling and drying air is conveyed through the apparatus with a minimum resistance so that the power requirements for a suction fan for passing the necessary cooling and drying air through the apparatus can be reduced to a minimum.

It is a further object of the present invention to provide for a combined drying and cooling apparatus of the type mentioned in which only the necessary part of the cooling air entering the apparatus at the lower end of the cooling zone is branched off at the upper end of the cooling zone to be heated and passed through the drying zone of the apparatus.

- It is an additional object of the present invention to regulate the amount Olf cooling air which may enter from the upper end of the cooling zone directly into the lower end of the drying zone without being heated so as to establish in the drying zone the right temperature for properly drying the material passing thereth-rough.

With these objects in view, the apparatus of the present invention for drying and cooling particulated material comprises an elongated substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding particulated material to be dried and cooled into the housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from the housing. The apparatus includes further chamber means surrounding the housing in the region where the drying zone borders the cooling zone and this chamber means has an upper end communicating with the drying zone and a lower end communicating with the cooling zone. Distributor means are provided in the interior of the housing to cause the material entering through the inlet opening to pass in finely divided form through the drying and the cooling zone. Cooling air is admitted through a cooling inlet means into the lower end of the housing so that the cooling air will pass in countercurrent to the particulate-d material upwardly through the cooling zone, and cooling air outlet means communicate with the interior of the housing in the region of the lower end of the chamber means for discharging part of the cooling air from the interior of the housing. The apparatus includes further deflector means in the housing in the region of the lower end of the chamber means for deflecting another part of the cooling air into the chamber means, and heating means are provided in the chamber means for heating the cooling air deflected thereinto so that the thus heated air will pass through the upper end of the chamber means into the drying zone for drying the particulated material passing therethrough, heating thereby the particulated material so that the cooling air before being deflected into the chamber means will be preheated by heat exchange with heated material passing through the cooling zone. Finally, the apparatus includes also air discharge means communicating at the upper end of the housing with the interior thereof for discharging the heated air from the housing after it has been passed through the heating zone.

The distributor means in the interior of the housing may include a plurality of preferably frustoconical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of the housing and a lower end defining a free cross section of smaller area than the upper end, and the aforementioned deflector means is preferably formed by the lowermost of the frustoconical guide members in the drying zone. Preferably, the chamber means has a lower end formed by a downwardly tapering frustoconical Wall spaced from the upper edge of the lowermost of the guide members in the drying zone to define with the lower edge of the aforementioned frustoconical wall of the chamber means an annular gap through which the chamber means communicates with the upper end of the cooling zone.

This arrangement results in deflection of part of the cooling air into the chamber means with a minimum of flow resistance and this arrangement will also reduce the necessary energy for properly heating the drying air in the chamber means to the necessary proper temperature, since the air deflected into the chamber means to be heated by the heating means therein is already preheated by heat exchange with the particulated material passing through the cooling zone.

If, for instance, a combined drying and cooling apparatus according to the present invention has to be constructed for a throughput of approximately 10 tons per hour of sugar crystals, whereby the sugar is fed at a temperature of approximately 50 C. and with a water content of 1.2% into the upper end of the drying zone, whereas the sugar should leave the lower end of the cooling zone at a temperature of about 40 C. and with a water content of 0.1%, approximately 16,500 NmF/h. (cubic meters under normal pressure per hour) of cooling air at a temperature of 25 C. will have to be fed into the lower end of the cooling zone, whereas only 5,000 Nmfi/h. at C. are necessary for the proper drying of the sugar in the drying zone. If the cooling air is fed into the lower end of the cooling zone at a temperature of 25 C., it will be preheated by heat exchange with the sugar passing through the cooling zone and reach at the upper end of the cooling zone a temperature of about 60 0., since the sugar leaves the drying zone at a temperature of about 65 C. With the apparatus of the present invention it is therefore only necessary to heat 5,000 Nm. /h. entering the chamber means only from 60 C. to 75 C. and this necessary raise of the temperature can be carried out easily by the heating means in the chamber means.

While part of the cooling air entering the lower end of the cooling zone is discharged at the upper end of the cooling zone to the outside of the apparatus and while another part is deflected into the chamber means to be heated by the heating means therein before it is passed through the drying zone, provisions have also to be made to regulate the amount of cooling air which can pass from the upper end of the cooling zone directly into the drying zone through the passages provided the interior of the housing which permit the material to pass from the drying zone into the cooling zone.

The apparatus of the present invention includes therefore also axially adjustable baffle means coaxial with the lowermost of the guide members of the drying zone which are located in the path of the particulated material, and the baffle means preferably taper in upward direction so that the particulated material impinging thereon will flow in a curtain-like manner onto the lowermost of the guide members of the drying zone and the thus formed curtain of particulated material will substantially prevent any passage of air from the upper end of the cooling zone directly into the drying zone. By axially adjusting the baflle means relative to the respective guide member it is possible to adjust the length of the aforementioned curtain of material flowing from the baflfle means onto the guide member and thereby it is possible to adjust the amount of air which is permitted to flow from the upper end of the cooling zone directly in the drying zone.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which the only figure is a partly sectioned side view of the apparatus of the present invention.

Referring now to the drawing, it will be seen that the apparatus of the present invention comprises an elongated, preferably cylindrical substantially vertical housing having a lower portion 1b defining a cooling zone 2 and an upper portion 1a defining a drying zone 3. The upper end of the drying zone 3 is closed by a cover plate 10 in which an inlet opening 11 is provided for feeding the particulated material, for instance sugar crystals, to be dried and cooled in the apparatus in the interior of the housing. The lower end of the housing is preferably of substantially conical configuration and is provided with a discharge opening 38 for discharging the material after it has passed through the apparatus therefrom. Distributor means are provided in the interior of the housing to cause the material entering in the inlet opening 11 to pass in finely divided form through the drying and cooling zone. The distributor means include preferably a plurality of substantially frustoconical guide members 6 arranged vertically spaced from each other and each connected at its upper end of larger diameter to the inner surface of the housing and each of the frustoconical guide members 6 tapering from the upper end toward the lower end of smaller diameter. The distributor means include further a plurality of plate members 5 respectively arranged in the frustoconical guide members 6 and each having an outer upwardly curved edge spaced from the wall of the respective guide member and having a diameter greater than the diameter of the lower end of the guide member above the respective plate member. An elongated shaft 4 mounted turnably about its axis on a plurality of bearings 7 is coaxially arranged within the housing extending longitudinally therethrough and the plate members 5 are fixed to the shaft 4 for rotation therewith. The shaft 4 is driven by motor 8 over a gear transmission 9 mounted on the top plate 10 of the housing. The necessary cooling air is passed through one or more conduits 12, two of which are shown in the drawing, into the lower end of the cooling zone 2 and the conduits 12 form cooling air inlet means for the apparatus. Filters may be provided in the conduits 12 to prevent entrance of dust together with the cooling air into the apparatus. Cooling air outlet means 13 communicate through an opening 14 at the upper end of the cooling zone with the latter to discharge part of the cooling air into a conduit 15. Another part of the cooling air is deflected through an annular gap 16 into chamber means surrounding the housing in the region where the drying zone 3 borders the cooling zone 2. The chamber means is formed by a substantially cylindrical wall 28 coaxial with the housing and closed at its upper end by a preferably removable cover 28. The deflection of part of the cooling air into the chamber means is produced by the lowermost of the frustoconical guide members 18 of the drying zone, the upper edge of which defines with a frustoconical wall 17 of the chamber means the annular gap 16 through which part of the cooling air at the upper end of the cooling zone passes into the chamber means.

The guide member 18 with its opening 19 forms a passage for the particulated material from the drying zone 3 into the cooling zone 2. The substantially prevent passage of cooling air from the cooling zone directly into the drying zone 3 or to regulate the amount of cooling air which is permitted to pass in this way directly from the cooling zone into the drying zone, a cylindrical socket member 20 is connected to the guide member 18 extending downwardly therefrom and the socket member 20 has a downwardly tapering bottom end 21. Furthermore, substantially conical bafile plates 22 and 23 are respectively arranged in the guide member 18 and in the socket member 20. The bafi le plates 22 and 23 are arranged in the path of the particulated material, that is the particulated material leaving the guide member 6a above the bafile plate 22 will drop at the upper surface of the latter and slide in form of a curtain 26 onto the guide member 18, drop from there onto the baflie plate 23 so that the material dropping from the baflle plate 23 onto the frustoconical end portion 21 of the socket member 20 will form a second material curtain 27, and the curtains 26 and 27 will substantially prevent any passage of cooling air from the upper end of the cooling zone directly into the drying zone through the annular gaps 24 and 25 respectively formed between the outer edges of the baffle plates 22 and 23 and the guide member 18 and socket member 20, respectively. The baflle plates 22 and 23 are fixed to the shaft 4 for rotation therewith and preferably, the position of the baflle plates 22 and 23 may be adjusted in axial direction of the shaft so that the size of the annular gaps 24 and 25 may be adjusted thereby.

The cooling air deflected by the guide member 18 into the chamber means is heated therein by heating means 30 provided in the chamber means, which may consist of steam heated conduits, and the thus heated air passes into the lower end of the heating zone 3 through an annular opening 31 which provides communication between the upper end of the chamber means and the lower end of the cooling zone 3. The heated passes in upward direction through the heating zone 3 and is discharged at the upper end of the heating zone through air discharge means 32 connected to the conduit 33. The conduit 33 is joined with a conduit 15 by a connector 34 to which a suction producing means in form of a suction fan 35 is connected which discharges the air into the atmosphere or into a non-illustrated dust remover. A pair of adjustable flow regulating means in form of flap valves 36 and 37 are preferably provided in the conduits 15 and 33, respectively, to regulate the flow of air passing through those conduits.

The operation of the apparatus described above will be obvious from the preceding description. The material to be dried, for instance sugar crystals, is continuously fed through the inlet opening 11 into the upper end of the apparatus and the material drops thus onto the uppermost of the plates 5 which is rotated at high speed by the motor 8 so that the material is thrown by centrifugal action onto the guide member 6 in which the uppermost plate 5 is located to drop from the uppermost guide member 6 onto the plate 5 therebelow, and so on, so that the material passes in finely divided form from the upper to the lower end of the apparatus. The particulated material in passing through the drying zone 3 is dried therein by the heated air passing therethrough in countercurrent to the material and the heated and dried material passes, while forming curtains 26 and 27, from the lower end of the drying zone into the cooling zone 2, where the dried and heated material is cooled by heat exchange with the cooling air passing in upward direction through the cooling zone 2. The properly dried and cooled material is discharged then through the discharge opening 38 at the bottom of the apparatus. The cooling air entering at the lower end of the cooling zone is preheated by heat exchange with the particulated material passing in countercurrent to the cooling air through the cooling zone and part of the cooling air is discharged through the cooling air outlet means 13 at the upper end of the cooling zone, while part of the preheated cooling air is deflected in the chamber means to be heated therein by the heating means to the necessary temperature for properly drying the material passing through the drying zone. The material curtains 26 and 27 formed by the material during its passage from the drying into the cooling zone will substantially prevent any cooling air from passing directly from the upper end of the cooling zone into the drying zone, but by adjusting the gaps 24 and 25 a predetermined amount of cooling air may be permitted to pass directly from the upper end of the cooling zone into the drying zone.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of apparatus for drying and cooling of particulated material differing from the types described above.

While the invention has been illustrated and described as embodied in apparatus of drying and cooling particulated material, especially sugar crystals, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

For instance the apparatus according to the present invention may also include distributor means of different type as described above, for instance the plates 5 which are rotated about their axes may be omitted and the distributor means may include only frustoconical guide members or guid members of slightly different shape for causing the material to pass in finely divided form through the apparatus.

Iclaim:

1. Apparatus for drying and cooling particulated material comprising, in combination, an elongated substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with said drying zone and a lower end communicating with said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heated material passing through said cooling zone; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated air therefrom.

2. Apparatus for drying and cooling particulated material comprising, in combination, an elongated substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with said drying zone and a lower end communicating with said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means, said deflector means being formed by the lowermost of said guide members in said drying zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heated material passing through said cooling zone; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated air therefrom.

3. Apparatus for drying and cooling particulated material comprising, in combination, an elongated cylindrical substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; cylindrical chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with the lower end of said drying zone and a lower end formed by a downwardly tapering frustoconical wall communicating with the upper end of said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular frustoconical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means, said deflector means being formed by the lower most of said guide members in said drying zone, the upper edge of said lowermost of said guide members in said drying zone defining with the lower edge of said frustoconical wall an annular gap through which said chamber means communicates with the upper end of said cooling zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heat-ed material passing through said cooling zone; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated air therefrom.

4. An apparatus as set forth in claim 3, wherein said chamber means extends downwardly beyond the lower edge of said frustoconical wall and wherein said cooling air outlet means is in the form of a conduit having a bottom portion in line with the lower end of said chamber means.

5. Apparatus for drying and cooling particulated material comprising, in combination, an elongated cylindrical substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; cylindrical chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with the lower end of said drying zone and a lower end formed by a downwardly tapering fr-ustoconical wall communicating with the upper end of said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular frustoconical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; a cooling air outlet conduit communicating at one end thereof with the interior of said housing in the region-of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means, said deflector means being formed by the lowermost of said guide members in said drying zone, the upper edge of said lowermost of said guide members in said drying zone defining with the lower edge of said fruustoconical wall an annular gap through which said chamber means communicates with the upper end of said cooling zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchannge with heated material passing through said cooling zone; an air discharge conduit communicating at one end thereof with the interior of said housing at the upper end thereof for discharging the heated air therefrom; a common suction producing means connected to the other end of said cooling air outlet conduit and to the other end of said air discharge conduit; and a pair of adjustable flow regulating means respectively arranged in said cooling air outlet conduit and in said air discharge conduit for regulating the flow of air passing respectively through said conduits.

6. Apparatus for drying and cooling particulated ma- .terial comprising, in combination, an elongated substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with said drying zoneand a lower end communicating with said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means, said deflector means being formed by the lowermost of said guide members in said drying zone, said lowermost guide member in said drying zone defining a passage through which particulated material passes from said drying zone into said cooling zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated matenial passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heated material passing through said cooling zone; means cooperating with said lowermost guide member for adjusting the free cross section of said passage; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated airvtherefrom.

7. Apparatus for drying and cooling pa'rticulated material comprising, in combination, an elongated cylindrical substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; cylindrical chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with the lower end of said drying zone and a lower end formed by a downwardly tapering fustoconical wall communicating with the upper end of said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular frusto-conical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means, said deflector means being forced by the lowermost of said guide members in said drying zone, the upper edge of said lowermost of said guide members in said drying zone defining with the lower edge of said frustoconical wall an annular gap through which said chamber means communicates with the upper end of said cooling zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heated material passing through said cooling zone; axially adjusta'ble baflle means coaxial with the lowermost of the guide members of said drying zone, said baffle means being located in the path of said particulated material and defining with the said lowermost guide member an adjustable annular gap through which the particulated material passes from said drying zone into said cooling zone; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated air therefrom.

'8. Apparatus for drying and cooling particulated material comprising, in combination, an elongated cylindrical substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled mate-rial from said housing; cylindrical chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with the lower end of said drying zone and a lower end formed by a downwardly tapering frustoconical Wall communicating with the upper end of said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular frustoconical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflect-ing another part of said cooling air into said chamber means, said deflector means being formed by the lowermost of said guide members in said drying zone, the upper edge of said lowermost of said guide members in said drying zone defining with the lower edge of said frustoconical wall an annular gap through which said chamber'means communicates with the upper end of said cooling zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat ex change with heated material passing through said cooling zone; a socket member extending downwardly from the lowermost of said guide members in said drying zone and having a downwardly tapering bottom end; a first axially adjustable substantially conical bafile plate coaxially arranged with said lowermost guide member and having a lower free edge defining a first annular gap with said lowermost guide member; a second axially ad justable conical baffle plate in said socket member and having a lower free edge defining with said tapering bottom end thereof a second annular gap and the particulated material passes from said drying into said cooling zone through said first and second annular gap; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated air therefrom.

9. Apparatus for drying and cooling particulated material comprising, in combination, an elongated cylindrical substantially vertical housing having an upper drying zone and a lower cooling zone and having an inlet opening at the upper end thereof for feeding material to be dried and cooled into said housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; cylindrical chamber means surrounding said housing in the region where said drying zone borders said cooling zone, said chamber means having an upper end communicating with the lower end of said drying zone and a lower end formed by a downwardly tapering frustoconical wall communicating with the upper end of said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said distributor means including a plurality of annular frustoconical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smaller area than said upper end thereof and each guide member tapering from said upper to said lower end, an elongated shaft extending longitudinally through said housing coaxially arranged therewith, means mounting said shaft turnably about its axis, motor means operatively connected to said shaft for rotating the same about its axis, a plurality of plate members respectively arranged in said guide members coaxial therewith and fixed to said shaft for rotation therewith, each of said plate members having an outer curved edge portion spaced from the wall of the respective guide member and having a diameter greater than the diameter of the lower end of the guide member above the respective plate member; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; cooling air outlet means communicating with the interior of said housing in the region of said lower end of said chamber means for discharging part of the cooling air from the interior of said housing; deflector means in said housing in the region of said lower end of said chamber means for deflecting another part of said cooling air into said chamber means, said deflector means being formed by the lowermost of said guide members in said drying zone, the upper edge of said lowermost of said guide members in said drying zone defining'with the lower edge of said frustoconical wall an annular gap through which said chamber means communicates with the upper end of said cooling zone; heating means in said chamber means for heating the cooling air deflected into said chamber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heated material passing through said cooling zone; asocket member extending downwardly from the lowermost of said guide members in said drying zone and having a downwardly tapering bottom end; a first axially adjustable substantially conical baffle plate coaxially arranged with said lowermost guide member and having a lower free edge defining a first annular gap with said lowermost guide member; a second axially adjustable conical baflle plate in said socket member and having a lower free edge defining with said tapering bottom end thereof a second annular gap and the particulated material passes from said drying into said cooling zone through said first and second annular gap; and air discharge means communicating with the interior of said housing at the upper end thereof for discharging the heated air therefrom.

10. Apparatus for drying and cooling particulated material comprising, in combination, an elongated cylindrical substantially vertical housing having an upper drying zone and a lower cooling zone and having an'inlet opening at the upper end thereof for feeding material to be dried and cooled into said'housing and a discharge opening at the lower end thereof for discharging the dried and cooled material from said housing; cylindrical chamber means surroundingsaid'housing in the region where said drying zone borders said cooling zone, said 'chamber means having an upper end communicating with the lower end of said drying zone and a lower end formed by a downwardly tapering frustoconical wall communicating with the upper end of said cooling zone; distributor means in the interior of said housing to cause the material entering through said inlet opening to pass in finely divided form through said drying and said cooling zone, said dis tributor means including a plurality of annular frustoconical guide members arranged spaced from each other in vertical direction and having each an upper end connected to the inner surface of said housing and a lower end defining a free cross section of smal er area than said upper end thereof and each guide member tapering from said upper to said lower end, an elongated shaft extending longitudinally through said housing coaxially arranged therewith, means mounting said shaft turnably about its axis, motor means operatively connectedto said shaft for rotating the same about its axis, a plurality of plate members respectively arranged in said guide members coaxial therewith and fixed to saidshaft for rotation therewith, each ofsaid plate members having an outer curved edge portion spaced from the wallofthe respective guide member and having a diameter greater than the diameter of the lower end of the guide 'member. above the respectiveplate member; cooling air inlet means for feeding cooling air into the lower end of said housing so that the cooling air will pass in countercurrent to the material upwardly through said cooling zone; a cooling air outlet conduit communicating at one.end thereof vwith the interior of said housing in the region of said lower end of said chamber means for discharging ,part of the cooling air from the interior of said housing;.deflector means in said housing in the region of said. lower end of said chamber means for deflecting another part of said coolingair into said chamber means, said, deflector means being formed by the lowermost of said guide members in said dryingzone, the upper edge of said lowermost of said guide members in said drying zone defining with the lower edge of said frustoconical wall an annular gap through which said chamber means communicates with the upper end ofIsaid cooling zone; heating means in said chamber means for heating the cooling air deflectedinto said'charnber means, so that the thus heated air will pass through said upper end of said chamber means into said drying zone for drying the particulated material passing therethrough heating thereby the particulated material and so that the cooling air before being deflected into said chamber means will be preheated by heat exchange with heated material passing through said cooling zone; a socket member extending downwardly from the lowermost of said guide members in said drying zone and 'having a downwardlyvtapering,bottom end; a first axially adjustable substantially conical baffle plate coaxially arranged with said lowermost guide member and having a lower free edge defining a first annular gap with said lowermost guide member; a second axially adjustable conical baflie plate in said; socket member andhaving a lower free edge defining with said tapering. bottom end thereof a second annular gap and theparticulated material passes from said drying into said cooling zone through said first and second annular gap; an air discharge conduit communicating at one end thereof with the interior of said housing at the upper end thereof'for discharging the heated air therefrom; a common suction producing means connected to the other end of said cooling air outlet conduit and to the other end of said air discharge conduit; and a pair of adjustable flow regulating means respectively arranged in said cooling air outletconduit and in said air discharge conduit forregulating the flow of air passing'respectively throughsaid conduits.

References Cited bytheExaminer UNITED STATES PATENTS 463,246 3/1937 Sangwin 34l71 2,627,399 11/1947 De Vaney 263-30 WILLIAM F. ODEA, Primary Examiner.

C. R. REMKE, Assistant Examiner. 

1. APPARATUS FOR DRYING AND COOLING PARTICULATED MATERIAL COMPRISING, IN COMBINATION, AN ELONGATED SUBSTANTIALLY VERTICAL HOUSING HAVING AN UPPER DRYING ZONE AND A LOWER COOLING ZONE AND HAVING AN INLET OPENING AT THE UPPER END THEREOF FOR FEEDING MATERIAL TO BE DRIED AND COOLED INTO SAID HOUSING AND A DISCHARGE OPENING AT THE LOWER END THEREOF FOR DISCHARGING THE DRIED AND COOLED MATERIAL FROM SAID HOUSING; CHAMBER MEANS SURROUNDING SAID HOUSING IN THE REGION WHERE SAID DRYING ZONE BORDERS AND COOLING ZONE, SAID CHAMBER MEANS HAVING AN UPPER END COMMUNICATING WITH SAID DRYING ZONE AND A LOWER END COMMUNICATING WITH SAID COOLING ZONE; DISTRIBUTOR MEANS IN THE INTERIOR OF SAID HOUSING TO CAUSE THE MATERIAL ENTERING THROUGH SAID INLET OPENING TO PASS IN INFINELY DIVIDED FORM THROUGH SAID DRYING AND SAID COOLING ZONE; COOLING AIR INLET MEANS FOR FEEDING COOLING AIR INTO THE LOWER END OF SAID HOUSING SO THAT THE COOLING AIR WILL PASS IN COUNTERCURRENT TO THE MATERIAL UPWARDLY THROUGH SAID COOLING ZONE; COOLING AIR OUTLET MEANS COMMUNICATING WITH THE INTERIOR OF SAID HOUSING IN THE REGION OF SAID LOWER END OF SAID CHAMBER MEANS FOR DISCHARGING PART OF THE COOLING AIR FROM THE INTERIOR OF SAID HOUSING; DEFLECTOR MEANS IN SAID HOUSING IN THE REGION OF SAID LOWER END OF SAID CHAMBER MEANS FOR DEFLECTING ANOTHER PART OF SAID COOLING AIR INTO SAID CHAMBER MEANS; HEATING MEANS IN SAID CHAMBER MEANS FOR HEATING THE COOLING AIR DEFLECTED IN TO SAID CHAMBER MEANS, SO THAT THE THUS HEATED AIR WILL PASS THROUG SAID UPPER END OF SAID CHAMBER MEANS INTO SAOID DRYING ZONE FOR DRYING THE PARTICULATED MATERIAL AND SO THAT THE HEATING THEREBY THE PARTICULATED MATERIAL AND SO THAT THE COOLING AIR BEFORE BEING DEFLECTED INTO SAID CHAMBER MEANS WILL BE PREHEATED BY EXCHANGE WITH HEATED MATERIAL PASSING THROUGH SAID COOLING ZONE; AND AIR DISCHARGE MEANS COMMUNICATING WITH THE INTERIOR OF SAID HOUSING AT THE UPPER END THEREOF FOR DISCHARGING THE HEATED AIR THEREFROM. 